Two-stage, sequential operation protective assemblies are provided, including a primary protective device having an element which shifts in response to operation thereof ), together with a secondary protective device. Such compounds possess both muscarinic receptor antagonist and \u03b22 adrenergic receptor agonist activities. A set of nearest items to the selected item is provided as a recommendation to the user of other items that may be of particular interest or relevance to the user’s original selection based upon the conceptual similarity measure. Therefore, the phase jitter in the steady state can be reduced. Particularly, the LEDs are embedded in the light transmissive material and arranged in a matrix.